In recent years, in a variety of sensors and wirings of automobiles, corrugated tubes that cover them are used. As shown in FIG. 10, for example, a corrugated tube 100 that covers an oxygen sensor includes an intermediate-diameter cylindrical portion 101, a large-diameter cylindrical portion 102, and a bellows portion 103 located between the intermediate-diameter cylindrical portion 101 and the large-diameter cylindrical portion 102. The corrugated tube is lightweight, flexible, and resistant to heat, and thus can protect the oxygen sensor for a long time.
In production of a corrugated tube, as shown in FIG. 11, a straight tube is fused by heating means, and high-pressure air is blown into the inside of the tube, whereby the shape of a molding die is transferred. The corrugated tube thus has seal portions 201 and 202 at opposite ends for sealing the high-pressure air. Such seal portions 201 and 202 are unnecessary parts and therefore cut off. Specifically, the corrugated tube 1 has to be cut at two places a and b at axially opposite ends at right angles relative to an axial direction 203.
As a method of cutting a rubber molded product, a cutting apparatus has been known that has a function of rotating a cut target that is an elastic work placed thereon, and includes a fixing device body for placing the center of the cut target in alignment with the center of rotation, two or more fixing arms installed on the fixing device body, a contact detection sensor provided on the fixing arm for detecting contact on the fixing arm, and a movable cutter provided independently of the fixing device body (JP-A-2006-159326).